Check out http://sanpaku72.blogspot.com/2007/09/having-fun-with-xaml-silverlight-and.html
It has a link to http://members.chello.nl/~a.degreef/xaml/xaml2svg.xsl and download the other xsl files by following the includes, like http://members.chello.nl/~a.degreef/xaml/xaml2svg/animation.xsl